Radar Micro-Doppler Phase Feature Extraction for Real-Time Activity Classification

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Solution Overview

Problem

Current radar-based human activity recognition methods using Micro-Doppler signatures require significant computational resources, making real-time classification on embedded platforms challenging due to complex classification algorithms and high computational demands.

Innovation Solution

A method that utilizes phase information from Micro-Doppler spectrograms to achieve high accuracy in human activity classification by converting amplitude spectrogram images to grayscale, applying binary image masks to identify Regions Of Interest (ROI), and calculating geometric and textural features, which are then classified using a trained classifier, reducing computational resources and enabling real-time implementation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If complex classification algorithms are used to improve human activity recognition accuracy, then classification accuracy is improved, but computational resources and device complexity increase significantly

Engineering Contradiction:
Improvehuman activity recognition accuracyVSAvoidcomputational resources requirement
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts only the essential phase information from the complete micro-Doppler spectrogram, discarding redundant amplitude and color information. By taking out only the necessary phase data and applying binary masking to identify regions of interest, the system reduces computational complexity while maintaining high recognition accuracy above 80%.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the representation parameters from full-color spectrogram images to grayscale images with binary masks. This parameter transformation simplifies the data structure and reduces the computational burden on classification algorithms, enabling real-time processing on embedded platforms while preserving the essential characteristics needed for accurate human activity recognition.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If complex classification algorithms are used to improve human activity recognition accuracy, then classification accuracy is improved, but processing time and real-time capability deteriorate

Engineering Contradiction:
Improvehuman activity recognition accuracyVSAvoidprocessing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent performs preliminary actions by converting the spectrogram to grayscale and applying binary masks to identify regions of interest before feeding data to the classification algorithm. This pre-processing simplifies the input data structure and reduces the computational time required for classification, enabling real-time processing while maintaining accuracy above 80%.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

By extracting only the phase information and creating binary masks of regions of interest, the patent reduces the amount of data that needs to be processed in real-time. This extraction approach significantly decreases processing time and makes the system suitable for embedded platforms with limited computational power.

Inventive Principle:
Principle #2Taking out (Extraction)

3Loss of information

If amplitude spectrogram images are processed directly, then more information is available, but computational complexity and processing requirements increase

Engineering Contradiction:
Improveinformation availabilityVSAvoidcomputational resources requirement
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

The patent extracts only the phase information from the amplitude spectrogram, discarding the amplitude data. This extraction is justified because phase information contains the essential characteristics needed for human activity recognition, while amplitude information proves to be redundant. The resulting binary masked phase images require significantly fewer computational resources for processing.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent transforms the parameter space from amplitude-based representation to phase-based representation. This parameter change simplifies the data structure and reduces computational requirements, as phase information provides sufficient discriminative power for activity classification without needing to process the more complex amplitude variations.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The method achieves over 80% accuracy in human activity recognition with significantly reduced computational resources, facilitating real-time classification and embedding on platforms, surpassing current techniques in both accuracy and efficiency.

Implementation Method 1

Radar is becoming increasingly irreplaceable in this field due to its unique advantages... uses the Micro-Doppler signature, which is a powerful representation of body micro-motions, synthesizing the Doppler components induced by different body parts

Methodology Applied
Scientific EffectDoppler effect: Doppler Effect

Data Source

PatentEP4194886A1Method and device for human activity classification using radar micro doppler and phase
Publication Date: 2023.06.14 ECOLE NAT SUPERIEURE DE LELECTRONIQUE & DE SES APPL
  • EP4194886A1 patent drawingFigure 1
  • EP4194886A1 patent drawingFigure 2
  • EP4194886A1 patent drawingFigure 3(a)~3(f)

AI summary

The invention relates to a method (100) of classifying in real-time human activity from a micro-Doppler signature image based on features extracted from phase information and unwrapped phase information. The invention relates also to a device for characterizing in real-time a human activity comprising : a radar (2) transmitting and receiving radar signals having a software interface for configuring the form of the transmitted signal and processing and calculation means (3) coupled to the radar, configured to, in real-time, implementing the method.